PROJECT ABSTRACT The International Immunocompromised Host Society (ICHS) will host the 20th International Symposium on Infections in the Immunocompromised Host in Athens, Greece from June 17-19, 2018. The symposium will be comprised of workshops, round tables, industry-sponsored symposiums, lectures, plenary sessions, meet the professor sessions, and two poster sessions. In addition, to commemorate the 20th ICHS Symposium, past ICHS presidents will present on the ICHS successes and challenges during their tenure. These individuals represent the ?thought-leaders? in the field; their historical contributions hold great relevance to the attendees ? both seasoned investigators and trainees. The 20th Symposium is estimated to be attended by 400 international delegates from over 40 countries and will focus on the latest advances, treatments, and topics relevant to the immunocompromised host to a global audience. Highlights from the 20th symposium include recent updates on advances in diagnostic tools for medical mycology, whole genome sequencing applications for studying infectious diseases, the emergence of fungal and bacterial resistance, viral reactivation in immunocompromised patients, and current treatments and their associated risks to the immunocompromised patient. Past support from the NIH have been invaluable for supporting the cost of travel for new investigators, trainees, women, and underrepresented individuals to attend. The 20th Symposium will continue to promote interactions between researchers and clinicians from all over the world as well as facilitate interactions between junior and more experienced investigators.